Exhaust system component structure

ABSTRACT

An exhaust system component structure is provided. The structure has an exhaust passage through which exhaust of an internal combustion engine passes, is configured by a plurality of exhaust components, and includes: an upstream pipe having an upstream passage constituting the exhaust passage; a downstream pipe having a downstream passage constituting the exhaust passage; a first fixing surface provided on the upstream pipe and a second fixing surface provided on the downstream pipe, fixed so that the upstream passage and the downstream passage are in communication with each other. A projection part projecting from the first fixing surface on an outer side of the upstream passage toward the downstream pipe is provided. The projection part is provided with a protrusion part projecting toward an outer side of the exhaust passage. A groove part is provided at a position facing the protrusion part in the downstream pipe.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Japan application serial no. 2020-056041, filed on Mar. 26, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND Technical Field

The disclosure relates to an exhaust system component structure configured by fixing two exhaust components to each other.

Description of Related Art

Conventionally, in the case of fastening pipes of exhaust system components, such as a turbocharger, a catalyst converter, etc., a technique of aligning flanges of the pipes and fastening the pipes by using a V-band (see Patent Document 1, for example) has been proposed. In Patent Document 1, the flange of the pipe of the turbocharger on the upstream side and the flange of the pipe of the catalyst converter on the downstream side are aligned and then fastened by using a V-band.

-   [Patent Document 1] Japanese Patent Laid-open No. 2019-157789A

In the conventional process for fastening the exhaust system components, at the time of the operation of fastening the pipe on the downstream side to the pipe on the upstream side, the flange of the pipe on the upstream side and the flange of the pipe on the downstream side need to be held in the state of being aligned. Therefore, a special holding jig may be required. In such case, the issue of a low operation efficiency arises.

SUMMARY

The disclosure has been made in view of the above issue, and provides an exhaust system component structure which facilitates the operation efficiency when two exhaust system components are assembled.

According to a first embodiment of the disclosure, an exhaust system component structure is provided and has an exhaust passage through which exhaust of an internal combustion engine (“engine” in the embodiment, the same applies to the following) passes and configured by a plurality of exhaust components. The exhaust system component structure includes: a first exhaust component (upstream pipe 10) having a first passage (upstream passage 11) constituting the exhaust passage; a second exhaust component (downstream pipe 20) having a second passage (downstream passage 21) constituting the exhaust passage; and a first fixing surface 13 provided on the first exhaust component and a second fixing surface 23 provided on the second exhaust component. The first fixing surface and the second fixing surface are fixed so that the first passage and the second passage are in communication with each other. A projection part 16 projecting from an outer side of the first passage on the first fixing surface 13 toward the second exhaust component is provided. The projection part 16 is provided with a protrusion part 17 projecting toward an outer side of the exhaust passage. A groove part 25 is provided at a position facing the protrusion part 17 in the second exhaust component 20.

Accordingly, since the groove part of the second exhaust component is provided at the position facing the protrusion part provided on the first exhaust component, when the second exhaust component is assembled to the first exhaust component, by locking the groove part to the protrusion part, the second exhaust component is maintained in a state of being temporarily fixed to the first exhaust component. Accordingly, the operation efficiency at the time of assembling the two exhaust system components can be facilitated.

According to a second embodiment of the disclosure, in the exhaust component structure as described in first embodiment, when the first fixing surface 13 and the second fixing surface 23 are fixed to each other, the protrusion part 17 is fit into the groove part 25 at a position on an outer side of the second passage.

Accordingly, in the case where the first fixing surface and the second fixing surface are fixed to each other, the protrusion part is fit into the groove part at a position on the outer side of the second passage. Thus, the protrusion part does not obstruct the flow of the exhaust in the exhaust passage.

According to a third embodiment of the disclosure, an exhaust system component structure is provided. The exhaust system component structure has an exhaust passage through which exhaust of an internal combustion engine (engine) passes, is configured by a plurality of exhaust components (upstream pipe 10, downstream pipe 20), and includes: a first exhaust component (upstream pipe 10) having a first passage (upstream passage 11) constituting the exhaust passage; a second exhaust component (downstream pipe 20) fixed to the first exhaust component and having a second passage (downstream passage 21) constituting the exhaust passage; and a first fixing surface 13 provided on the first exhaust component and a second fixing surface 23 provided on the second exhaust component. The first fixing surface and the second fixing surface are fixed so that the first passage and the second passage are in communication with each other. A projection part 16 projecting from an outer side of the first passage on the first fixing surface 13 toward the second exhaust component is provided. The projection part 16 is provided with a protrusion part 17 projecting toward an outer side of the exhaust passage. A groove part 25 is provided at a position facing the protrusion part 17 in the second exhaust component 20. When the first fixing surface 13 and the second fixing surface 23 are fixed to each other, the protrusion part 17 is fit into the groove part 25 at a position on an outer side of the second passage.

Accordingly, since the groove part of the second exhaust component is provided at the position facing the protrusion part provided on the first exhaust component, when the second exhaust component is assembled to the first exhaust component, by locking the groove part to the protrusion part, the second exhaust component is maintained in a state of being temporarily fixed to the first exhaust component. Accordingly, the operation efficiency at the time of assembling the two exhaust system components can be facilitated. In addition, in the case where the first fixing surface and the second fixing surface are fixed to each other, when the protrusion part 17 is fit into the groove part 25 at the position on the outer side of the second passage, the protrusion part 17 does not obstruct the flow of the exhaust in the exhaust passage.

According to a fourth embodiment of the disclosure, in the exhaust system component structure as described in any one of first to third embodiments, the first exhaust component is disposed upstream of the second exhaust component in a direction in which the exhaust flows, and the second exhaust component is fixed to the first exhaust component.

Accordingly, with the configuration in which the first exhaust component is disposed on the upstream side and the second exhaust component is fixed to the first exhaust component, the groove part of the second exhaust component can be locked to the protrusion part of the first exhaust component and thus be locked easily, the efficiency of the assembling operation can be facilitated.

According to a fifth embodiment of the disclosure, in the exhaust system component structure as described in any one of first to fourth embodiments, the exhaust passage is configured to be cylindrical, the protrusion part 17 is configured to be arc-shaped, the groove part 25 is configured to be arc-shaped or circular, and a bottom diameter of the groove part 25 is configured to be greater than an outer diameter of the protrusion part 17. A length of the protrusion part 17 in a width direction orthogonal to a height direction in which the protrusion part 17 projects is smaller than a length between two points intersecting with an outer diameter of the protrusion part 17 and a bottom diameter of the groove part 25 in a case where the second exhaust component is moved an amount of a height of the protrusion part 17.

Accordingly, by making the length of the protrusion part in the width direction smaller than the length between two points intersecting with the outer diameter of the protrusion part and the bottom diameter of the groove part when the second exhaust component is moved the amount of the height of the protrusion part, at the time of performing the operation of assembling the groove part to the protrusion part or performing the operation of removing the assembly, since the protrusion part does not interfere with the groove part, the operation can be performed smoothly. Moreover, since the length between the two points intersecting with the outer diameter of the protrusion part and the bottom diameter of the groove part can be set to be greater, the strength of the protrusion part can be ensured, and the holdability at the time of detachment of the second exhaust component can be ensured.

According to a sixth embodiment of the disclosure, in the exhaust system component structure as described in any one of first to fifth embodiments, the exhaust passage is configured to be cylindrical, the protrusion part 17 is configured to be arc-shaped, the groove part 25 is configured to be arc-shaped or circular, and in a case where a bottom diameter of the groove part 25 is set as D₁, an outer diameter of the protrusion part 17 is set as D₂, and a length of a movement when the second exhaust component is detached from the first exhaust component is set as Y, a length X of the protrusion part 17 in a width direction orthogonal to a height direction in which the protrusion part 17 projects is defined according to a formula as follows:

${X = {D_{2} \times \sin\frac{\left\lbrack {{180} - \left\{ {2 \times {\sin^{- 1}\left( \frac{D_{1}^{2} - D_{2}^{2} - {4Y^{2}}}{4 \times D_{2} \times Y} \right)}} \right\}} \right\rbrack}{2}}}.$

Accordingly, when the length of the protrusion part in the width direction is set, at the time of performing the operation of assembling the groove part to the protrusion part or performing the operation of removing the assembly, since the protrusion part does not interfere with the groove part, the operation can be performed smoothly. Moreover, since the length between the two points intersecting with the outer diameter of the protrusion part and the bottom diameter of the groove part can be set to be greater, the strength of the protrusion part can be ensured, and the holdability at the time of detachment of the second exhaust component can be ensured.

According to a seventh embodiment of the disclosure, in the exhaust system component structure as described in any one of first to sixth embodiments, the groove part 25 is provided across an entirety in a direction orthogonal to a direction in which the exhaust flows.

By forming the groove part across the entirety in the direction orthogonal to the direction in which the exhaust flows, when the groove part of the second exhaust component is assembled to the protrusion part of the first exhaust component, the second exhaust component can be assembled to the first exhaust component at any angle. Accordingly, the operation efficiency can be facilitated.

According to an eighth embodiment of the disclosure, in the exhaust system component structure as described in any one of first to seventh embodiments, in order to fasten the first exhaust component and the second exhaust component to each other by using a V-band, a first inclination surface 19 is provided at an outer end part of the first exhaust component, and a second inclination surface 29 is provided on an outer end part of the second exhaust component.

Accordingly, by forming the first inclination surface of the first exhaust component and the second inclination surface of the second exhaust component, the first exhaust component and the second exhaust component can be fastened to each other by using a V-band. Combined with the operation of assembling the first exhaust component and the second exhaust component, the assembling operation of fixing the first exhaust component and the second exhaust component can be efficiently performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view illustrating an exhaust system component structure according to an embodiment.

FIG. 2 is a cross-sectional view illustrating an exhaust system component structure according to an embodiment.

FIGS. 3A to 3D are views illustrating an order of assembling an exhaust system component structure according to an embodiment.

FIG. 4 is a view illustrating a length as a reference when a length in a width direction of a protrusion part is calculated.

DESCRIPTION OF THE EMBODIMENTS

In the following, the exemplary embodiment of the disclosure will be described in detail with reference to the drawings. An exhaust system component structure of the embodiment is configured by a plurality of exhaust components having a cylindrical exhaust passage through which the exhaust of an internal combustion engine (engine) passes. FIG. 1 is an oblique view illustrating an exhaust system component structure according to an embodiment. FIG. 2 is a cross-sectional view illustrating an exhaust system component structure according to an embodiment. As shown in FIG. 1 and FIG. 2, the exhaust components are configured by an upstream pipe 10 having a cylindrical upstream passage 11 forming the exhaust passage and a cylindrical downstream pipe 20 having a downstream passage 21 forming the exhaust passage.

The upstream pipe 10 is a pipe disposed on the upstream side in the direction in which the exhaust from the engine flows, such as a pipe of a turbocharger. The upstream pipe 10 has an upstream flange 12 so as to be fixed to the downstream pipe 20. An end surface of the upstream flange 12 facing the downstream pipe 20 is a first fixing surface 13. In addition, the upstream pipe 10 has a taper-shaped first inclination surface 19 formed at an outer end part of the upstream pipe 10, more specifically, at an outer diameter end part of the upstream flange 12 and on a back side of the first fixing surface 13.

The downstream pipe 20 is a pipe disposed on the downstream side in the direction in which the exhaust from the engine flows, such as a pipe of a catalyst converter. The downstream pipe 20 has a downstream flange 22 so as to be fixed with respect to the upstream pipe 10. An end surface of the downstream flange 22 facing the upstream pipe 10 is a second fixing surface 23. In addition, a taper-shaped second inclination surface 29 is formed at an outer end part of the downstream pipe 20, more specifically, at an outer diameter end part of the downstream flange 22 and on a back side of the second fixing surface 23.

With such configuration, the first fixing surface 13 formed at the upstream flange 12 abuts against the second fixing surface 23 formed at the downstream flange 22, and the upstream pipe 10 and the downstream pipe 20 are fixed with each other. Accordingly, the upstream passage 11 of the upstream pipe 10 and the downstream passage 21 of the downstream pipe 20 are in communication with each other. In addition, when the upstream pipe 10 and the downstream pipe 20 are fixed, the first inclination surface 19 and the second inclination surface 29 are combined, and the first inclination surface 19 and the second inclination surface 29 form a convex part whose cross-section exhibits a V-shape. Therefore, the upstream pipe 10 and the downstream pipe 20 can be fastened to each other by a V-band.

When being assembled before being fixed to each other, the upstream pipe 10 and the downstream pipe 20 have a configuration in which a portion of the downstream pipe 20 is hooked to the upstream pipe 10 to temporarily hold the downstream pipe 20. Specifically, a groove part 25 formed on the downstream pipe 20 is hooked to a locking part 15 formed on the upstream pipe 10 (as indicated by arrows of FIG. 1 and FIG. 2), so as to temporarily hold the downstream pipe 20. Details in this regard will be described in the following.

The locking part 15 formed on the upstream pipe 10 is formed on the upstream flange 12 and is formed at a position on a radially outer side with respect to the upstream passage 11 having a circular cross-section and at the top of the drawing. The locking part 15 is formed by a projection part 16 and a protrusion part 17. The projection part 16 is formed on the first fixing surface 13 on a radially outer side with respect to the upstream passage 11, and projects in a direction toward the downstream pipe 20 (a direction toward the downstream side along the direction in which the exhaust flows). In addition, at the downstream side end part of the projection part 16, the protrusion part 17 which projects toward the radially outer side and on an outer side with respect to the exhaust passage is formed. A cross-section of the protrusion part 17 on a surface parallel to the first fixing surface 13 is formed to be arc-shaped.

The groove part 25 formed on the downstream pipe 20 is formed on an inside of the downstream pipe 20 with respect to the second fixing surface 23 of the downstream flange 22 (the downstream side in the direction in which the exhaust flows). The groove part 25 is configured to have a bottom diameter greater than the diameter of the downstream passage 21 having a circular cross-section. In addition, the groove part 25 is formed across the entirety in a direction orthogonal to the direction in which the exhaust flows. In the embodiment, the groove part 25 is formed, in the circumferential direction, on the entire inner circumference of the downstream passage 21.

Nevertheless, it may also be that the groove part 25 is not formed on the entire circumference, but is formed on a portion along the circumferential direction of the downstream passage 21 and provided with an arc-shaped cross-section on a surface parallel to the second fixing surface 23. Here, in the case where the groove part 25 is formed to be arc-shaped, the groove part 25 may be formed on at least a portion above the downstream passage 21.

Then, the order of assembling the upstream pipe 10 and the downstream pipe 20 will be described in the following. FIGS. 3A to 3D are views illustrating an order of assembling an exhaust system component structure according to an embodiment. In the embodiment, the order of assembling the downstream pipe 20 with respect to the upstream pipe 10, which has been disposed, is described as an example.

As shown in FIG. 3A, before being assembled, the downstream pipe 20 approaches the upstream pipe 10. At this time, the downstream pipe 20 approaches so that the first fixing surface 13 of the upstream pipe 10 and the second fixing surface 23 of the downstream pipe 20 face each other.

As shown in FIG. 3B, the downstream flange 22 of the downstream pipe 20 approaches the upstream flange 12 of the upstream pipe 10. At this time, the downstream flange 22 approaches, so that the groove part 25 of the downstream pipe 20 is positioned above the locking part 15 of the upstream pipe 10.

As shown in FIG. 3C, when the downstream pipe 20 is lowered, the groove part 25 of the downstream pipe 20 is hooked to the protrusion part 17 of the upstream pipe 10. Accordingly, the downstream pipe 20 can be temporarily held with respect to the upstream pipe 10.

As shown in FIG. 3D, in the state in which the downstream pipe 20 is temporarily held with the upstream pipe 10, the downstream pipe 20 is moved to the side of the upstream pipe 10. Accordingly, the second fixing surface 23 of the downstream pipe 20 is combined with the first fixing surface 13 of the upstream pipe 10, and the first fixing surface 13 and the second fixing surface 23 can be fixed with each other. In this case, since the protrusion part 17 is fit into the groove part 25, the flow of the exhaust in the exhaust passage is not obstructed.

In addition, in the state in which the first fixing surface 13 and the second fixing surface 23 are combined, the first inclination surface 19 is combined with the second inclination surface 29, and the first inclination surface 19 and the second inclination surface 29 form the convex part whose cross-section exhibits a V-shape. Therefore, the upstream pipe 10 and the downstream pipe 20 can be fastened to each other by a V-band 30.

A process for determining the length of the width direction of the protrusion part 17 will be described in the following. In the protrusion part 17 of the embodiment, a length X of the width direction of the protrusion part 17 is determined according to the following, so that the downstream pipe 20 is easy to detach from the upstream pipe 10. FIG. 4 is a view illustrating a length as a reference when the length X in the width direction of the protrusion part 17 is calculated. Here, the width direction is shown as a direction (left-right direction in the figure) orthogonal to the height direction (top-down direction in the figure) in which the protrusion part 17 projects.

As described above, in the embodiment, the upstream passage 11 of the exhaust passage is formed to be cylindrical, the protrusion part 17 is formed to be arc-shaped, and the groove part 25 is formed to be circular. In addition, a bottom diameter D₁ of the groove part 25 is formed to be greater than an outer diameter D₂ of the protrusion part 17. In this case, the length X of the width direction of the protrusion part 17 is configured to be smaller than a length between two points intersecting with the outer diameter D₂ of the protrusion part 17 and the bottom diameter D₁ of the groove part 25 when the downstream pipe 20 is moved an amount of the height of the protrusion part 17. Here, the downstream pipe 20 being moved the amount of the height of the protrusion part 17 indicates a movement when the downstream pipe 20 is detached from the upstream pipe 10, and refers to the case of moving from the state of FIG. 3C to the state of FIG. 3B.

Therefore, the length X of the width direction of the protrusion part 17 is represented in a formula in the following. In the following formula, D₁ represents the bottom diameter of the groove part 25, D₂ represents the outer diameter of the protrusion part 17, and Y represents the length of the movement when the downstream pipe 20 is detached from the upstream pipe 10,

${X = {D_{2} \times \sin\frac{\left\lbrack {{180} - \left\{ {2 \times {\sin^{- 1}\left( \frac{D_{1}^{2} - D_{2}^{2} - {4Y^{2}}}{4 \times D_{2} \times Y} \right)}} \right\}} \right\rbrack}{2}}}.$

As described above, according to the embodiment, since the groove part 25 of the downstream pipe 20 is configured as being formed at a position facing the protrusion part 17 formed on the upstream pipe 10, when the downstream pipe 20 is assembled to the upstream pipe 10, by locking the groove part 25 to the protrusion part 17, the downstream pipe 20 is maintained in the state of being temporarily fixed to the upstream pipe 10. Accordingly, the operation efficiency at the time of assembling the two exhaust system components (the upstream pipe 10 and the downstream pipe 20) can be facilitated.

In addition, in the case where the first fixing surface 13 and the second fixing surface 23 are fixed to each other, the protrusion part 17 is fit into the groove part 25 at a position on the outer side of the downstream passage 21. Accordingly, the protrusion part 17 does not obstruct the flow of the exhaust in the exhaust passage.

In addition, with the configuration in which the upstream pipe 10 is disposed on the upstream side, and the downstream pipe 20 is fixed to the upstream pipe 10, the grove part 25 of the downstream pipe 20 can be locked to the protrusion part 17 of the upstream pipe 10, which has been fixedly disposed, and thus be locked easily, and the efficiency of the assembling operation can be facilitated.

In addition, the length X of the protrusion part 17 in the width direction is configured to be smaller than the length between two points intersecting with the outer diameter D₂ of the protrusion part 17 and the bottom diameter D₁ of the groove part 25 when the downstream pipe 20 is moved the amount of the height of the protrusion part 17. Accordingly, at the time of performing the operation of assembling the groove part 25 to the protrusion part 17 or performing the operation of removing the assembly, since the protrusion part 17 does not interfere with the groove part 25, the operation can be performed smoothly. In addition, since the length X of the protrusion part 17 in the width direction can be set to be greater, the strength of the protrusion part 17 can be ensured, and the holdability when the downstream pipe 20 is detached can be ensured.

In addition, in the case where the bottom diameter of the groove part 25 is set as D₁, the outer diameter of the protrusion part 17 is set as D₂, and a length of a movement when a second exhaust component is detached from a first exhaust component is set as Y, at the time of setting the length X of the protrusion part 17 in the width direction orthogonal to the height direction in which the protrusion part 17 projects, by setting the length of the protrusion part 17 in the width direction according to a following formula, the protrusion part does not interfere with the groove part when the operation of assembling the groove part to the protrusion part is performed or when the operation of removing the assembly is performed, so the operation can be performed smoothly. In addition, since the length X of the protrusion part 17 in the width direction can be set to be greater, the strength of the protrusion part 17 can be ensured, and the holdability at the time of detachment of the downstream pipe 20 can be ensured,

${X = {D_{2} \times \sin\frac{\left\lbrack {{180} - \left\{ {2 \times {\sin^{- 1}\left( \frac{D_{1}^{2} - D_{2}^{2} - {4Y^{2}}}{4 \times D_{2} \times Y} \right)}} \right\}} \right\rbrack}{2}}}.$

The disclosure is not limited to the described embodiments, and can be carried out in various embodiments. For example, in the embodiment, the locking part 15 is formed on the upstream pipe 10, and the groove part 25 is formed on the downstream pipe 20. However, the disclosure is not limited thereto. It may also be that a groove part is formed on the upstream pipe 10, and a locking part formed by a projection part and a protrusion part is formed on the downstream pipe 20. 

What is claimed is:
 1. An exhaust system component structure, having an exhaust passage through which exhaust of an internal combustion engine passes and configured by a plurality of exhaust components, the exhaust system component structure comprising: a first exhaust component, having a first passage constituting the exhaust passage; a second exhaust component, having a second passage constituting the exhaust passage; and a first fixing surface provided on the first exhaust component and a second fixing surface provided on the second exhaust component, the first fixing surface and the second fixing surface being fixed so that the first passage and the second passage are in communication with each other, wherein a projection part projecting from the first fixing surface on an outer side of the first passage toward the second exhaust component is provided, the projection part is provided with a protrusion part projecting toward an outer side of the exhaust passage, and a groove part is provided at a position facing the protrusion part in the second exhaust component.
 2. The exhaust system component structure as claimed in claim 1, wherein when the first fixing surface and the second fixing surface are fixed to each other, the protrusion part is fit into the groove part at a position on an outer side of the second passage.
 3. The exhaust system component structure as claimed in claim 1, wherein the first exhaust component is disposed upstream of the second exhaust component in a direction in which the exhaust flows, and the second exhaust component is fixed to the first exhaust component.
 4. The exhaust system component structure as claimed in claim 3, wherein the exhaust passage is configured to be cylindrical, the protrusion part is configured to be arc-shaped, the groove part is configured to be arc-shaped or circular, a bottom diameter of the groove part is configured to be greater than an outer diameter of the protrusion part, a length of the protrusion part in a width direction orthogonal to a height direction in which the protrusion part projects is smaller than a length between two points intersecting with an outer diameter of the protrusion part and a bottom diameter of the groove part in a case where the second exhaust component is moved an amount of a height of the protrusion part.
 5. The exhaust system component structure as claimed in claim 4, wherein the exhaust passage is configured to be cylindrical, the protrusion part is configured to be arc-shaped, the groove part is configured to be arc-shaped or circular, and in a case where a bottom diameter of the groove part is set as D₁, an outer diameter of the protrusion part is set as D₂, and a length of a movement when the second exhaust component is detached from the first exhaust component is set as Y, a length X of the protrusion part in a width direction orthogonal to a height direction in which the protrusion part projects is defined according to a formula as follows, ${X = {D_{2} \times \sin\frac{\left\lbrack {{180} - \left\{ {2 \times {\sin^{- 1}\left( \frac{D_{1}^{2} - D_{2}^{2} - {4Y^{2}}}{4 \times D_{2} \times Y} \right)}} \right\}} \right\rbrack}{2}}}.$
 6. The exhaust system component structure as claimed in claim 5, wherein the groove part is provided across an entirety in a direction orthogonal to a direction in which the exhaust flows.
 7. The exhaust system component structure as claimed in claim 6, wherein in order to fasten the first exhaust component and the second exhaust component to each other by using a V-band, a first inclination surface is provided at an outer end part of the first exhaust component, and a second inclination surface is provided on an outer end part of the second exhaust component.
 8. An exhaust system component structure, having an exhaust passage through which exhaust of an internal combustion engine passes and configured by a plurality of exhaust components, the exhaust system component structure comprising: a first exhaust component, having a first passage constituting the exhaust passage; a second exhaust component, fixed to the first exhaust component and having a second passage constituting the exhaust passage; and a first fixing surface provided on the first exhaust component and a second fixing surface provided on the second exhaust component, the first fixing surface and the second fixing surface being fixed so that the first passage and the second passage are in communication with each other, wherein a projection part projecting from the first fixing surface on an outer side of the first passage toward the second exhaust component is provided, the projection part is provided with a protrusion part projecting toward an outer side of the exhaust passage, a groove part is provided at a position facing the protrusion part in the second exhaust component, and when the first fixing surface and the second fixing surface are fixed to each other, the protrusion part is fit into the groove part at a position on an outer side of the second passage.
 9. The exhaust system component structure as claimed in claim 8, wherein the first exhaust component is disposed upstream of the second exhaust component in a direction in which the exhaust flows, and the second exhaust component is fixed to the first exhaust component.
 10. The exhaust system component structure as claimed in claim 8, wherein the exhaust passage is configured to be cylindrical, the protrusion part is configured to be arc-shaped, the groove part is configured to be arc-shaped or circular, a bottom diameter of the groove part is configured to be greater than an outer diameter of the protrusion part, a length of the protrusion part in a width direction orthogonal to a height direction in which the protrusion part projects is smaller than a length between two points intersecting with an outer diameter of the protrusion part and a bottom diameter of the groove part in a case where the second exhaust component is moved an amount of a height of the protrusion part.
 11. The exhaust system component structure as claimed in claim 8, wherein the exhaust passage is configured to be cylindrical, the protrusion part is configured to be arc-shaped, the groove part is configured to be arc-shaped or circular, and in a case where a bottom diameter of the groove part is set as D₁, an outer diameter of the protrusion part is set as D₂, and a length of a movement when the second exhaust component is detached from the first exhaust component is set as Y, a length X of the protrusion part in a width direction orthogonal to a height direction in which the protrusion part projects is defined according to a formula as follows, ${X = {D_{2} \times \sin\frac{\left\lbrack {{180} - \left\{ {2 \times {\sin^{- 1}\left( \frac{D_{1}^{2} - D_{2}^{2} - {4Y^{2}}}{4 \times D_{2} \times Y} \right)}} \right\}} \right\rbrack}{2}}}.$
 12. The exhaust system component structure as claimed in claim 8, wherein the groove part is provided across an entirety in a direction orthogonal to a direction in which the exhaust flows.
 13. The exhaust system component structure as claimed in claim 8, wherein in order to fasten the first exhaust component and the second exhaust component to each other by using a V-band, a first inclination surface is provided at an outer end part of the first exhaust component, and a second inclination surface is provided on an outer end part of the second exhaust component. 